A 5D bend is a pipe bend that the bend radius is 3 times the pipe outside diameter.

What is 5D bend?

The RADIUS of a 5D bend is actually what is 5 times the nominal diameter. So if you had a 10″ diameter pipe, the radius of the centerline of the bend would be 50 inches.

How do you know a 3d or 5d bend?

It is the radius of pipe bend of the elbow with reference to a point,the point is determined by the intersection of two lines from the elbows socket end (which makes the shape of one quater of a circle). The bend ie; 1.5d,3d,5d,12d is determined from that point of intersection as a multiple of elbows diameter. Pipe bend, Bend pipe, Pipe bending, ANSI, ISO, JIS and DIN Standards, Measures 1/2 to 56 Inches.